Search PubMed⌕ Search

Biomedical subjects

I Diamantis

Publications and source records attributed to I Diamantis.

21 records · Page 2Linked to original sources

[Loss of ganglion cells in the retina secondary to vincristine therapy].

We report the case of a 25-year-old black female from Zaire with AIDS diagnosed 2 years earlier. Nine months before her death, she was treated for a disseminated Kaposi sarcoma with vincristin, adryamycin and bleomycin. At that time, visual acuity was normal and ophthalmologic examination was unremarkable except for the presence of bilateral Drusen and a cotton wool spot OS. Three months after the onset of chemotherapy, the patient complained of progressive visual field constriction, which progressed to blindness within a 4 month period. Five months after the onset of the tri-therapy a bilateral CMV retinitis developed, which was successfully treated by intravitreous injections of ganciclovir. This therapy was stopped as soon as blindness was established, with subsequent massive bilateral recurrence of the CMV retinitis. Histologic examination showed complete atrophy of the retinal ganglion cells and areas of CMV retinitis. The optic nerve was demyelinated and exhibited astrocytic gliosis. Immunohistochemistry confirmed the presence of CMV in infected retina and revealed the absence in the optic nerve of the class III beta-tubulin isotype and of the 200 kd neurofilament subunit. In contrast, oculomotor nerves appeared intact. The presence of HIV in the eye and in the optic nerve was excluded using PCR technique. The retinal ganglion cell loss and optic nerve atrophy appeared to be purely degenerative in nature, since there was no evidence of vascular occlusion, inflammation or retrobulbar compressive process. We therefore conclude that blindness was caused by vincristine therapy. The patient actually received 22 mg of vincristin intravenously in 11 courses over 7 months, although discontinuation was recommended by us after 5 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗

Migratory behavior of cells on embryonic retina basal lamina.

In order to study cell translocation in vitro on a physiological substrate a novel cell migration assay was developed using the inner limiting membrane of the avian embryonic retina. The matrix sheet consists of a laminin-rich basal lamina covered by a dense layer of neuroepithelial endfeet. The retina basal lamina does not contain fibronectin. Cells translocating on this substrate displace the neuroepithelial endfeet, leaving behind tracks in the endfeet monolayer. Motility of cells and the relative forward to lateral migration can be quantitated by measuring lengths, widths, and areas of the tracks. Using this assay system, the conditions and patterns of cell migration for a variety of cells have been examined. In the absence of serum all cell types show only minor migratory activity and addition of serum to the culture medium always enhances the rate of cell migration in a saturable, dose-response manner. The serum cannot be replaced by fibronectin or vitronectin (serum spreading factor). For maximum cell migration, serum has to be constantly present in the medium; however, 58% cell migration is obtained in serum-free medium when the matrix is preincubated with serum. According to the area and linearity of the tracks, the migratory behavior of the different cells can be classified into three groups: (i) fibroblasts and the nonpigmented Bowes melanoma cells form straight and long tracks; (ii) glioma, sarcoma, and carcinoma cells from straight but short tracks, and (iii) neuronal tumor cells, epithelial cells, and pigmented B16 melanoma cells form wide and short tracks. Comparative studies with low and high metastatic clones of tumorgenic cell lines show that migratory activity and metastatic potential of cells do not necessarily correlate. Finally, we show that fibroblasts deposit fibronectin fibrils on their paths as they migrate on the basal lamina. Fibronectin trails are also seen when fibroblasts are cultured on plain basal laminae that are pretreated with detergent to remove the endfeet monolayer. Likewise, when fibroblasts are cultured in the presence of antifibronectin antibodies, the fibronectin secreted by cells is detectable. Due to antibody treatment the cellular fibronectin is precipitated and its normal fibril formation is inhibited; however, the translocation of fibroblasts is not impaired.

Animals↗

Nasopharyngeal carcinoma: Epstein-Barr Virus significance.

Thirty-one cases of NPC were investigated by in situ hybridization, PCR analysis and serology to assess the presence of EBV and to interrelate these findings. Statistical analysis showed a significant correlation between the probability of detecting EBV and NPC. There was no significant association between in situ hybridization, PCR and serology. Tumor size correlated with EBNA, but no correlation between smoking and NPC was found.

Antibodies, Viral↗